Any feedback on GSO 10"RC

telecasterguru (Frank) · #1 06-01-2010, 02:15 PM

Just wondering if anyone had purchased one of the new 10" GSO RCs and if so they would mind giving some feedback as I am very interested in them.

Frank

Grahame (Grahame) · #2 13-01-2010, 03:20 PM

Jury must still be out on the 10's, I would say after this weekend there might be some feedback

Grahame.

Moon (James) · #3 13-01-2010, 04:53 PM

Yes...
http://www.cloudynights.com/ubbthrea.../o/all/fpart/1

multiweb (Marc) · #4 13-01-2010, 04:56 PM

Looks like the 10" is out at $3.9k but it's an alu-painted tube. The CF version is said to be for March 2010 and will be in excess of $4k. Maybe time to wait still?

mick pinner · #5 13-01-2010, 05:05 PM

so you need to drill holes in the focuser to stop lateral movement, what a winner of a scope. sounds cynical? oh yes.

mick pinner · #6 13-01-2010, 05:07 PM

am l missing something or have they been taken of the Atscope web site?

gregbradley · #7 14-01-2010, 05:35 AM

Its possible that flocking the secondary dewshield area may reduce those reflections. I have heard of that handling persistent reflection problems in an RC type scope before. Something is probably unpainted or shiny in the optical train. Perhaps also the baffle tube could be flocked but I'd start with the secondary shield. Then if no joy I'd look through the optical train for any other bright metal areas.

The suggestion it has something to do with pixels in that report is very humorous. I have never seen that before and used lots of CCD cameras.

It is true some filters reflect worse than others. Baaders and Astronomiks and FLI research grade filters are known for good performance in this area.

Greg

Moon (James) · #8 15-01-2010, 01:41 PM

Quote:

am l missing something or have they been taken of the Atscope web site?

Interesting. Peter - do you care to stop us speculating?

On CN they are talking about a 16 inch truss verison by the end of the year for $7995.

Moon (James) · #9 15-01-2010, 01:56 PM

Quote:

The suggestion it has something to do with pixels in that report is very humorous. I have never seen that before and used lots of CCD cameras.

Then how to explain the grid shape of the reflections? (especially the 5th image) To me it looks like the type of reflections you might expect off a surface that was covered in micro lenses acting as prisms (the sensor) then reflecting back off the filter or some other glass in the optical path.

Quote:

I have never seen that before and used lots of CCD cameras.

I have never seen it before either - that's why it's so interesting

telecasterguru (Frank) · #10 15-01-2010, 02:30 PM

I am amazed at the amount of work required to make the scope road worthy. Hopefully a lot of these issues will be fixed when the carbon fibre tube OTAs arrive.

I might wait for the 16" and by the time it is ready I may have enough for a deposit.

Frank

AlexN · #11 15-01-2010, 03:10 PM

The focuser is the biggest problem with them from what I understand... The reflections shown in the images on CN happen in newts and SCT's too.. its generally a reflection of the primary in the secondary.. I've seen it with plenty of different optical systems.

The sagging focuser is an issue, but its easily sorted out... a 3" Feathertouch will hole absolutely any load you throw at it, and considering the price of the scope in comparison to other 10" RC scopes, you're looking at $4600 with a 3" FT... If you flocked the 2ndry and whacked on a good focuser you could be looking at a very nice scope...

Take Paul Haese's 8" GSO RC... His had reflection issues and focuser issues when he got it... it's now producing epic images with the scope just from a new focuser and flocking.. The revised 8" had a baffle that does not need baffling, however the focuser on the revised scope is still not capable of holding a serious camera setup.. for a DSLR it might be fine, but for a mono CCD, filter wheel and an OAG the focuser is horribly inadequate.. Having said that, most consumer scopes have average focusers that are not capable of holding a big imaging setup, the fact is that on a short focal length scope the affects are nowhere near as noticeable as they are with these longer focal length scopes.

telecasterguru (Frank) · #12 15-01-2010, 09:40 PM

Alex,

I was unaware that feathertouch made a focuser for this scope although I thought that it would happen in time.

I have looked on their site and could not see what I thought was an appropriate focuser.

I was of the opinion that back focus would be a problem and this has also made me hesitant.

Also using a 5DII with small pixels on such a long focul length may be less than ideal.

I really want one of these scopes and if feathertouch can supply the goods then the deal will surely be done. I have heard some very good things about the optics of these OTAs.

I think that if I get one of these RCs with my ED127 then I will have all the bases covered. (until something else comes along)

Frank

AlexN · #13 16-01-2010, 12:56 AM

You wouldnt have super-wide field covered mate...

I have my 480mm focal length APO, will be getting the ED127 and then will look into getting another 8" RC or a 10" maybe...

The 3" feather touch focuser can easily be used on the 10" RC, all you need to do is find out what the rear thread is on the RC, then contact starlight instruments and request an adapter be made from that thread to the 3" FT... They already make the adapter for a 2" Feathertouch to the 8", although a 2" focuser will vignette the 5D sensor.. So it would be better to go to a 3"..

As for the small pixels with a long focal length - don't worry about it.. Oversampling is great... just make sure your guiding is tight!!

Tandum (Robin) · #14 16-01-2010, 01:21 AM

I'd prefer a Vixen VMC260L. Native FL of 2990mm at F11 or 1850mm with F7 reducer and a 60mm hole in the arse end. 10Kgs.

AlexN · #15 16-01-2010, 01:39 AM

Very true Robin, the VMC260L @ F/7 would be an amazing imaging scope.. very large corrected image field, light weight and optics are reportedly every bit as nice as the VC200L...

The downside to the VMC260L is its price.. Although I've not checked it recently, I considered one when I bought my C11 and scarily enough, the C11 was much cheaper...

Tandum (Robin) · #16 16-01-2010, 04:35 AM

I see the C11 at almost $6K here. The Vixen is around the same price as this chinese RC and it has a reducer made for it.

el_draco (Rom) · #17 17-01-2010, 04:03 PM

You would think these manufacturers would start to get their equipment tested BEFORE they massed produced it. Gawd, you spend an arm and a leg, then toss in the other two just to fix the B.S. that ought to have been fixed with a little design testing. Getting tired of it?

Octane (Humayun) · #18 17-01-2010, 04:20 PM

I may have asked before, but, can someone explain to me what realistically the advantage is of one of these over a similar aperture Newtonian with a coma corrector?

The Newtonian would be faster, between 2 and 3 stops, and, a third to a quarter of the price.

Or, am I missing the point altogether?

H

AlexN · #19 17-01-2010, 05:00 PM

Focal length H.. Not only focal lenght, but size of the telescope too..

A 10" F8 newtonian would require a serious mount to stop any vibrations, would likely weigh a fair bit I'd say it wouldn't fit in most of our cars. Yes, the average 10" newt is F/4.7, so its faster, but the people buying these RC's aren't concerned about fast, they really want the longer focal length of these scopes...

Octane (Humayun) · #20 17-01-2010, 05:32 PM

Oh, OK. Gotcha.

In that case, what advantage do they have over a traditional Schmidt-Cassegrain?

H